This morning I woke up to start my Ubuntu 20.04 laptop, and all of a sudden my 2x2 workspace matrix became a column with 4 rows. My anger to this random change aside, the instructions I used the last time don't work any more. As I use Chrome, the relevant extension is https://extensions.gnome.org/extension/1485/workspace-matrix/, but whenever I restart Chrome, it just looks like this:
Same on Firefox. The plugin just don't stay active.
While I found some some errors relating to the workspaces via journalctl /usr/bin/gnome-shell, it turns out the solution was as easy as switching the Extensions on again in GNOME Tweaks. This also made the slider stay switched on in https://extensions.gnome.org/extension/1485/workspace-matrix/
I can only reason that some error in GNOME caused the Extensions to fail.
For reference, the error I found on the last session where the workspace matrix was still there:
Mär 12 14:40:20 panther3 gnome-shell[12492]: JS WARNING: [/home/panther/.local/share/gnome-shell/extensions/workspace-grid@mathematical.coffee.gmail.com/extension.js 1268]: reference to undefined property "_controls"
Mär 12 14:40:20 panther3 gnome-shell[12492]: JS ERROR: Extension workspace-grid@mathematical.coffee.gmail.com: TypeError: Main.overview._controls is undefined
overrideWorkspaceDisplay@/home/panther/.local/share/gnome-shell/extensions/workspace-grid@mathematical.coffee.gmail.com/extension.js:1268:25
enable@/home/panther/.local/share/gnome-shell/extensions/workspace-grid@mathematical.coffee.gmail.com/extension.js:1533:5
_callExtensionEnable@resource:///org/gnome/shell/ui/extensionSystem.js:167:32
loadExtension@resource:///org/gnome/shell/ui/extensionSystem.js:351:26
_loadExtensions/<@resource:///org/gnome/shell/ui/extensionSystem.js:601:18
collectFromDatadirs@resource:///org/gnome/shell/misc/fileUtils.js:27:17
_loadExtensions@resource:///org/gnome/shell/ui/extensionSystem.js:576:19
_enableAllExtensions@resource:///org/gnome/shell/ui/extensionSystem.js:610:18
_sessionUpdated@resource:///org/gnome/shell/ui/extensionSystem.js:641:18
init@resource:///org/gnome/shell/ui/extensionSystem.js:56:14
_initializeUI@resource:///org/gnome/shell/ui/main.js:257:22
start@resource:///org/gnome/shell/ui/main.js:146:5
@<main>:1:47
Mär 12 14:40:21 panther3 gnome-shell[12492]: GNOME Shell crashed with signal 11